a)
3a/(2a+25)
2a+25≠0
2a≠-25
a≠-25/2
a∈R\{-25/2}
б)
2y/(9+y²)
9+y²≠0
y²≠-9
y∈R
в)
5x/(3x(x+12))
3x(x+12)≠0
x≠0 ∧ x≠-12
x∈R\{-12,0}
г)
7a/(a+1)(a-4)
(a+1)(a-4)≠0
a≠-1 ∧ a≠4
a∈R\{-1,4}
a)
3a/(2a+25)
2a+25≠0
2a≠-25
a≠-25/2
a∈R\{-25/2}
б)
2y/(9+y²)
9+y²≠0
y²≠-9
y∈R
в)
5x/(3x(x+12))
3x(x+12)≠0
x≠0 ∧ x≠-12
x∈R\{-12,0}
г)
7a/(a+1)(a-4)
(a+1)(a-4)≠0
a≠-1 ∧ a≠4
a∈R\{-1,4}